Yang T.,GSK CNC Equipment Co.
Zhongguo Jixie Gongcheng/China Mechanical Engineering
In order to improve the machining precision of NC machine tool, a real-time error compensation function module was developed based on the bottom communication of CNC system. The error compensation module can exchange data with CNC system through GSK-Link network communication protocol. The machine temperature and the coordinate of each axis can be real-time collected through the temperature acquisition module and the data communications module. The compensation values can be calculated through error compensation module and can be delivered to the CNC system through PLC. The real-time error compensation can be realized through the external coordinate offset function. The error compensation results on GSK 25i CNC system shows that the real-time error compensation function module can improve the accuracy of machine tools effectively, and the machine tool errors can be reduced by 91.7% compared with without compensation. The error compensation module has strong practical values. Source
Li F.,South China University of Technology |
Li D.,South China University of Technology |
Huang X.,South China University of Technology |
Huang X.,GSK CNC Equipment Co.
Huanan Ligong Daxue Xuebao/Journal of South China University of Technology (Natural Science)
In order to avoid the low average feedrate, discontinuous machining path and strong vibration shock in the machining process of consecutive micro line blocks, a real-time smoothing interpolation method based on NURBS curve fitting is proposed. In this method, by analyzing the geometric characteristics and machining technique of the consecutive lines, a length ratio criterion and a critical angle criterion of adjacent lines are presented to pick out the appropriate point sequence. The point sequence is divided into many subsections based on the concave and convex criterion and is then fitted to obtain parametric curves. Finally, by combining the linear interpolation and the parametric curve interpolation, a high-speed smoothing machining is successfully implemented. Simulated and experimental results demonstrate that the proposed method effectively improves the machining speed, reduces the machining vibration and ensures the machining accuracy. Source
Zhou Y.,GSK CNC Equipment Co.
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering
In five-axis machining, the rotary axis motions bring up non-linear error which relates to federate, configuration of machine tools, and so on and is difficult to solve common analytical solution. Using five-axis function, CNC must calculate in real-time non-linear error and lamp real-time feederate accordingly. In consideration of generality and computational simplicity in CNC software implementation, path non-linear error can be approximated by the non-linear error in path midpoint instead of seeking analytical methods, and a practical heuristics to calculate clamped feederate based on error setting is proposed using an approximate relationship between speed and non-linear error, both engineering oriented method are proved to be reasonable by simulation of typical machining programs. © 2014 Journal of Mechanical Engineering. Source
Yang T.,GSK CNC Equipment Co. |
Feng J.,GSK CNC Equipment Co. |
Feng J.,Guangdong University of Technology
Zhongguo Jixie Gongcheng/China Mechanical Engineering
A Fairing method for dual-NURBS tool path was proposed, smoothing the break points where the accuracy was not satisfied with Bezier dual-quaternion vector function. With the proposed method, the accuracy and G1 continuity of the whole tool-path were attained. As a result, the needs for five-axis high-speed machining are met by eliminating the abrupt changes of the velocity direction, thus improving the servo dynamics and reducing the shock of the machine tool. Source
Chen W.-J.,Guangdong No.2 Provincial Peoples Hospital |
Xie X.-H.,GSK CNC Equipment Co. |
Li Y.-G.,Guangdong No.2 Provincial Peoples Hospital |
Liu T.-F.,GSK CNC Equipment Co. |
And 3 more authors.
Chinese Journal of Tissue Engineering Research
Background: Virtual knee arthroscopy system has achieved some preliminary research results at home and abroad, but it is still unable to be popularized and applied widely because of the high cost. Therefore, we designed a set of simulation endoscopic equipment, which allows the surgeons to promote surgery skills during virtual surgery. Objective: To evaluate the training effect of virtual knee arthroscopy system on surgical skills of the beginning students. Methods: Twenty-four interns and orthopedists (16 interns with no arthroscopy operating experience; eight experts with arthroscopy operating experience) were selected from five different universities and different hospitals, and 16 interns were randomly divided into training group and control group, eight interns in each group. After system training, the training group was compared with the control group and expert group in the virtual knee arthroscopy system operation and clinical surgery operation, and the results were statistically processed. Results and Conclusion: In the virtual endoscope system operation, there was significant difference in the scores between the control and training groups (P < 0.001), and also between the control and expert groups (P < 0.001); however, there was no significant difference in the scores between the training and expert groups (P=0.115). In the clinical knee arthroscopy operation, there were significant differences between the training and control groups (P < 0.001), between the control and expert groups (P < 0.001), and between the training and expert groups (P=0.03). Virtual knee arthroscopy system can serve as beneficial surgery skill training for beginning students and the improvement of virtual operation technique may be related to clinical skills. Source